Carburetor temperature control



Nov. 15, 1966 c. F. HUDDLE 3,285,588

CARBURETOR TEMPERATURE CONTROL Filed Sept. 29, 1965 w I INVENTOR.

@rZ/zfzad/e 319 14/ By 312 gym 4 7'TORNEY United States Patent Ofitice3,285,588 Patented Nov. 15, 1966 3,285,588 CARBURETOR TEMPERATURECONTROL Carl F. Huddle, Pleasant Ridge, Mich., assignor to GeneralMotors Corporation, Detroit, Mich., a corporation of Delaware FiledSept. 29, 1965, Ser. No. 491,315 4 Claims. (Cl. 261-130) This inventionrelates to means for regulating the temperature of an internalcombustion engine carburetor and is directed more particularly to meanswhich reduce heat flow from the engine to the carburetor after thecarburetor has been heated to a predetermined temperature.

Automotive engines are subjected to such extremes of operatingtemperatures that it is diflicult to design a carburetor which willfurnish the required air-fuel mixture to the engine under allconditions. For example, when the temperature is extremely low, it isusually necessary to heat the carburetor to prevent the formation of icein the low pressure regions of the mixture conduit and to promotevaporization of the fuel in the air-fuel mixture. On the other hand,complex arrangement-s of vents and valves are occasionally necessary toprevent the large volume of fuel vapor, formed in the fuel bowl and fuelpassages at high temperatures, from over-enriching the mixture.

This invention provides easily regulated means for controlling theoperating temperature of a carburetor so that the complex vapor handlingand heating arrangements may be simplified. -In the disclosed embodimentof this invention, an insert, secured between the carburetor and theengine, has a series of heat-radiating fins which reduce heat transferfrom the engine to the carburetor. The temperature of the carburetor isthus maintained well below the normal engine operating temperature. Athermostatically operated cover is provided to enclose the fins, therebypreventing heat radiation until the carburetor is heated to apredetermined point. This invention thus permits the temperature of thecarburetor to be maintained in a range in which carburetor icing isprevented and in which fuel vaporization is promoted to the desiredextent.

The details as well as other objects and advantages of this inventionare disclosed in the specification and in the drawing in which:

FIGURE 1 is a side elevational view, partially in sec tion, of oneembodiment of this carburetor temperature control; and

FIGURE 2 is a view taken along line 22 of FIGURE 1 illustrating theoperation of the cover.

FIGURE 1 of the drawing illustrates a conventional internal combustionengine carburetor having a mixture conduit 12 and a fuel supply systemincluding a fuel bowl 14 and a fuel passage 16 through which fuel isconducted from the fuel bowl 14 to a venturi 18 formed in mixtureconduit 12. A throttle 20 controls the flow of air-fuel mixture throughthe mixture conduit 12.

Carburetor 10 is secured to the upper flange 21 of an insert 22 which isin turn mounted by a lower flange 23 upon the intake manifold 24 of aninternal combustion engine. Insert 22 has a conduit 26 through which theair-fuel mixture is conducted from mixture conduit 12 to the intakemanifold 24. A plurality of heat-radiating fins 28 are secured aboutconduit 26 of insert 22 to form a series of annular surfaces about whichair may circulate to reduce heat transfer through the insert.

A'pair of semi-circular cover sections 30 and 32 surround fins 28 andare hinged together by a pin 34 supported in a lateral extension 36 ofthe lower flange 23. A spring 38 biases cover sections 30 and 32 toenclose fins 28, preventing air circulation about fins 28 and permittingthe carburetor to be rapidly heated to a desired operating temperature.

A pair of coiled bi-metallic thermostats 40 are secured to the top fin28 beneath dome-shaped portions 42 and 44 of cover sections 30 and 32.As shown in FIGURE 2, links 46 extend from thermostats 40 to coversections 30 and 32 to open cover sections 30 and 32 and expose fins 28when a desired operating temperature is reached. Air circulation aboutthe fins then removes heat from insert 22 to reduce heat transfer fromengine intake manifold 24 to carburetor 10. Thus, excess evaporation offuel in fuel bowl 14 and fuel passage 16 is avoided.

While many difierent arrangements may be devised for securing fins 28about conduit 26 in the insert 22, in the illustrated embodiment eachfin 28 is formed as two semi-circular halves 28a and 28b secured by acylindrical flange 48, as shown in FIGURE 1, to cylindrical mountingelements 50. Mounting elements 50 are received in a groove 52 formed inlower flange 23 and are supported at the upper end by a snap ring 54. 1

It will be appreciated that this invention thus provides a simplyconstructed insert which effectively controls the temperature ofcarburetor 10 within a predetermined range. Those skilled in the artwill appreciate that this invention may be alternatively constructed byforming insert 22 as an integral portion of carburetor 10 withoutmaterially affecting the temperature control.

I claim:

1. Carburetion means adapted for mounting on an internal combustionengine comprising a mixture conduit, a fuel supply system including afuel bowl and .fuel passage means connecting said fuel bowl and saidmixture conduit, a plurality of fins extending outwardly from saidmixture conduit below said fuel supply system, said fins being adaptedto radiate heat into the surrounding air and reduce heat transfer fromthe engine to said fuel supply system, a cover surrounding said fins to:reduce heat radiation and promote fuel vaporization during lowtemperature conditions, and thermostatic means'connected to open saidcover and expose said fins during high temperature conditions.

2. The carburetion means of claim 1 wherein said thermostatic meansincludes a thermostat mounted adjacent said mixture conduit andoperating linkage connected to open said cover and expose said fins asthe temperature adjacent said mixture conduit increases.

3. The carburetion means of claim 1 wherein said cover includes a pairof hinged portions biased to enclose said fins, and wherein saidthermostatic means includes a pair of thermostats mounted adjacent saidmixture conduit and operating linkage connecting said thermostats withsaid cover portions to open said cover and expose said fins as thetemperature adjacent said mixture conduit increases.

4. A carburetor tempera-ture control insert adapted to mount acarburetor upon an internal combustion engine comprising first flangemeans for securing one end of said insert to the engine, second flangemeans for securing the carburetor to the opposite end of said insert,said insert including a cylindrical conduit through which an airfuelmixture may flow from the carburetor to the engine, a plurality of finsextending outwardly from the exterior of said conduit and forming aseries of annular surfaces adapted to radiate heat into the surroundingair and reduce heat transfer from the engine to the carburetor, a pairof hinged semi-circular cover portions surrounding said fins, a pair ofcoiled bimetallic thermostats secured to one of said fins adjacent saidconduit, links extending from said thermostats to said cover portions toopen said 'cover portions and expose said fins as the temperatureincreases, and spring means biasing said cover portions to enclose saidfins to reduce heat radiation and promote carburetor heating at'lowtemperatures.

References Cited by the Examiner UNITED STATES PATENTS 1,158,494 11/1915H-arroun 261-156 X 1,814,402 7/ 1931 Mullen 261130 1,879,551 9/1932Shoemaker 123122 ROBERT F. BURNETT, Primary Examiner.

RONALD R. WEAVER, Examiner.

1. CARBURETION MEANS ADAPTED FOR MOUNTING ON AN INTERNAL COMBUSTIONENGINE COMPRISING A MIXTURE CONDUIT, A FUEL SUPPLY SYSTEM INCLUDING AFUEL BOWL AND FUEL PASSAGE MEANS CONNECTING SAID FUEL BOWL AND SAIDMIXTURE CONDUIT, A PLURALITY OF FINS EXTENDING OUTWARDLY FROM SAIDMIXTURE CONDUIT BELOW SAID FUEL SUPPLY SYSTEM, SAID FINS BEING ADAPTEDTO RADIATE HEAT INTO THE SURROUNDING AIR AND REDUCE HEAT TRANSFER FROMTHE ENGINE TO SAID FUEL SUPPLY SYSTEM, A COVER SURROUNDING SAID FINS TOREDUCE HEAT RADIATION AND PROMOTE FUEL VAPORIZATION DURING LOWTEMPERATURE CONDITIONS, AND THERMOSTATIC MEANS CONNECTED TO OPEN SAIDCOVER AND EXPOSE SAID FINS DURING HIGH TEMPERATURE CONDITIONS.